Archive for the ‘Gear Review’ Category

HOW WE TEST MASKS

Mask Test Protocol:

To evaluate the in-water performance of each mask, a team of ScubaLab test divers dived with them at Alexander Springs in central Florida. Using underwater slates and waterproof test sheets, divers scored each mask in five performance categories. Our team of divers also recorded comments about their experience with each mask and ranked in order their top three favorites in each of two mask categories — dual-lens and single- lens models.

Ergo Test Categories:

Ease and security of adjustments, including buckles, swivels and quick releases

Comfort of the strap, skirt, frame, nose pocket and all contact points

Dryness overall, and effectiveness of seals and purge valves

Field of view, both vertical and horizontal

Mask volume and ease of clearing and equalizing

Because of the importance of proper fit, individual test divers did not proceed with in-water testing if a mask failed to fit him or her properly.

HOW WE SCORE MASKS

Shown on the graph accompanying each mask are that mask’s scores for comfort (including the strap, skirt, frame and contact points) and field of view (both horizontal and vertical, as perceived by the diver). The scoring is as follows: 5 = excellent; 4 = very good; 3 = good; 2 = fair; 1 = poor. Test divers also selected their top three favorite masks in each of the two test categories — dual lens and single lens.

MULTI-LENS VS. SINGLE LENS

The choice between mask types is partly a matter of personal preference and partly a function of special requirements a diver might have. Multi-lens masks, especially dual-lens models, generally have a smaller internal volume than single-lens models because their smaller size can allow them to be shaped closer to the diver’s face. A smaller volume is beneficial because it makes a mask easier to clear and equalize. They also can be equipped with corrective lenses, which many manufacturers offer for their most popular masks. Single-lens masks offer the widest uninterrupted field of view because they don’t have the obstruction of the nose bridge needed on a dual- or multi-lens mask. Single-lens masks can’t be fitted with corrective lenses and generally have somewhat larger volume, although many newer designs have significantly reduced volumes.

Q: What factors did test divers find most important?

A: Test divers’ favorite masks took top scores for comfort, with supple skirts, soft nose pockets and no hard parts contacting the face. That’s no surprise because an uncomfortable mask can quickly take the fun out of any dive.

Q: What are the pros and cons of frameless masks?

A: Molding the skirt directly to the lens gives the frameless mask a lower profile and eliminates any visual obstruction the frame might cause. Because the frameless masks’ lenses aren’t removable, they can’t be fitted with corrective lenses or replaced. — Roger Roy, ScubaLab Director

With so many regs to test in 2015, we split up our test, evaluating models under $500 (July) and over $500 (August).

How We Test Regulators

ScubaLab put these regs through two tests — the first is conducted on a breathing simulator (objective), and the second by our team of test divers (ergonomic).

Objective Testing

We conducted tests on an ANSTI wet breathing simulator at Dive Lab, a commercial test facility in Panama City Beach, Florida. The simulator measures the effort (work of breathing) required to move air through a regulator as it is subjected, under- water, to a precise series of depths and breathing rates.

The simulator pressurizes the test chamber to simulate depths of 132 fsw, 165 fsw and 198 fsw. Each “breath” by the machine moves 2.5 liters of air through the regulator, at breathing rates of 15, 25 and 30 breaths a minute. These precisely measured volumes of air — 2.5 liters multiplied by the breathing rate — are called Respiratory Minute Volumes (RMVs).

We don’t test on the simulator for a pass/fail grade, but to objectively gauge performance in carefully controlled conditions. You can see how each reg performed on the breathing simulator in the charts that accompany the reviews.

In our September/October issue we tested a dozen snorkels, including pocket models, for performance, comfort and convenience.

How We Test Snorkels

To evaluate the performance of each snorkel in open-water conditions, the ScubaLab team of test divers snorkeled of the beach at Sebastian Inlet State Park on Florida’s Atlantic Coast in seas of about 2 feet, with an onshore breeze of about 12 knots. Using waterproof test sheets and slates, divers rated each snorkel in seven performance categories, with 1 being poor performance and 5 being excellent. Divers also recorded comments about their experience using each snorkel and ranked their top three favorites in each category.

Ergonomic Test Categories

Security, adjustability, convenience and ruggedness of the mask attachment.

While we could have used tougher lines (such as Kevlar), we chose the lines we did because they’re the kind of cheap, often-discarded, long-lived materials that we encounter diving.

We made a first cut through a hand-held loop of each type of line, and rated the cutting ability from 1 to 5 (1=Poor and 5=Excellent). Next we cut a double thickness of each line, and then we made 20 repetitive cuts of all lines on a block of soft wood, and followed that with more cuts of hand-held loops (since you’re not likely to find a cutting board when diving). We also scored each knife on the following: the security of its sheath or folding/locking mechanism; the ease of deploying/stowing the knife barehanded and with 5 mm gloves; how it withstood 10 pounds of weight when wedged 1-inch deep in a block of wood; and its overall fit and finish.

In the market for new dive gear, but don’t have time to wait until the next ScubaLab Review? You’re in luck, because our ScubaLab Director hand-picked some of his favorite new dive gear on the market, plus a quick overview about the latest and greatest features! In this installment, we take a look at the ScubaPro travel bag, the Pinnacle Inferno V-Skin wetsuit, and the Underwater Kinetics Aqualite ELED Pro 20° dive light.

ANSTI breathing simulator results shown here are based on a score of 1 to 5, where 5 represents excellent performance with work-of-breathing measurements of 1 joule per liter or less at carefully regulated depths and breathing rates and volumes.

HOW WE TEST

ScubaLab put these regs through two tests — the first is conducted on a breathing simulator, and the second by our team of test divers.

OBJECTIVE TESTING

We conducted tests on an ANSTI wet breathing simulator at Dive Lab, a commercial test facility in Panama City Beach, Florida. The simulator measures the effort (work of breathing) required to move air through a regulator as it is subjected, under- water, to a precise series of depths and breathing rates.

The simulator pressurizes the test chamber to simulate depths of 132 fsw,165 fsw and 198 fsw. Each “breath” by the machine moves 2.5 liters of air through the regulator, at breath- ing rates of 15, 25 and 30 breaths a minute. These precisely measured volumes of air — 2.5 liters multi- plied by the breathing rate — are called Respiratory Minute Volumes (RMVs).

75 RMV @ 132 fsw:
This simulates the potential demand at maximum recreational depth for a diver at an extremely heavy work rate, or loosely simulates two divers buddy breathing at a somewhat aggressive rate.

62.5 RMV @ 165 fsw:
This represents the European conformance standard EN250, and is also the depth and breathing rate commonly used by manufacturers when determining a regulator’s performance.

62.5 RMV @ 198 fsw:
This is the U.S. Navy’s Class A test depth and breathing rate (although the Navy uses a higher HP supply pressure than we do). The simulator monitors how much effort is required to breathe, measuring the work of breathing in joules per liter (j/l). In our ratings, a score of 1=3j/l or greater; 2 = 2.26-3.0 j/l; 3 = 1.51-2.25 j/l; 4 = 1.1-1.50 j/l; and 5=1j/l or less.

We don’t test on the simulator for a pass/fail grade, but to objectively gauge performance in carefully controlled conditions. You can see how each reg performed on the breathing simulator in the charts that accompany the reviews.

ERGONOMIC TESTING

We conducted these tests at Alexander Springs in Florida with a team of divers who recorded their scores during their dives using underwater slates and waterproof test sheets. Divers evaluated each regulator in 13 specific performance areas, assigning scores from 5 (excellent) to1 (poor), and recording their observations and comments about factors that determine the comfort and performance of the reg while they were actually being used.

ERGO TEST CATEGORIES

1 Ease of breathing in swimming position
2 Ease of breathing in head-up position
3 Ease of breathing in head-down position
4 Wetness in normal swimming position
5 Wetness in head-down and odd positions
6 Bubble interference in normal swimming position
7 Bubble interference in vertical/stationary position
8 Ease of clearing regulator using the blowing method
9 Ease of clearing regulator using the purge button
10 Purge button stiffness and comfort
11 Comfort of mouthpiece
12 Venturi lever adjustment function and effectiveness
13 Breathing- adjustment-knob function and effectiveness

WHAT YOU GET FOR UNDER $500

Regs in this price range tend to be short on frills. None we tested in this price category had breathing resistance adjustments, rotating first stages, swivel hose connections, titanium goodies, etc. In some cases, that means you’re giving up a bit of comfort or convenience, such as the additional options for hose routing that you get with a rotating first stage, or the ability to precisely fine-tune your reg’s breathing resistance at a particular depth and workload. But that’s not to say these regs cut corners when it comes to performance — in our testing some showed work-of- breathing scores on the ANSTI machine and comfort and ease of breathing in the ergo tests to rival regs with much heftier price tags. Of course, their lack of breathing resistance adjustments means it’s especially important that their factory presets strike the right compromise between too much and too little at varying depths and breathing rates. Our testing suggests they usually hit very close to the mark.

WHAT YOU GET FOR OVER $500

The regs we tested in this price range showed slightly higher performance overall on the breathing simulator than their thriftier brethren (principally at greater depths and extreme breathing rates). But testers found that some features on these regs added comfort and convenience. Breathing adjustments allowed fine-tuning airflow with changes in depth or breathing demands. Exotic materials helped keep components light for comfort without sacrificing performance or durability. And first-stage features like rotating barrels or extra ports provided more hose-routing options.

While our test-team divers were impressed with the performance of the $500-and-under regulators, they found that some of the extras that come with these pricier models really are well worth it.

Q: What makes a reg a favorite?

A: As you’d expect for a piece of gear as personal as a reg, test divers have varying opinions. But the regs our testers liked best had controls that were easy to use and effective (and well marked). They had second stages that were compact and didn’t create bubble interference. They had purge controls that could clear the reg effectively without an excessive blast of air. And — above all else — they delivered smooth, quiet breathing, with as little effort as possible.
— Roger Roy, ScubaLab Director

Our divers liked regs with a light-weight second stage, an easy, predictable purge, controls that are effective and easy to adjust, and smooth, steady breathing without a lot of noise.

REG CLEANING

Don’t just give your reg a quick rinse after diving — give it a good long soak, especially if you’ve done multiple dives in salt water. Always be sure to give clean, fresh water time to wash away any salt that has accumulated before it can cause corrosion or other damage to sensitive parts such as valves and diaphragms. If possible, soak your reg while it’s installed on a tank and pressurized, which will prevent water from getting inside. If it’s not pressurized, don’t press the purge while it’s soaking because that could let water inside.

No piece of dive gear is more important to keep in proper working condition than your reg. Inspect it carefully before every use, clean it thoroughly after diving, and have it serviced at intervals the manufacturer recommends.

PERFORMANCE YOU CAN SEE

The graphs below show results of ANSTI testing on the same reg at different depths and breathing rates. The loops go clockwise, starting at the right, as inhalation begins, and moving to the left, where exhalation starts. Below the centerline shows the negative pressure required to inhale; above shows the positive pressure needed to exhale, measured in millibars.

Photo Illustration by Scubadiving.com

ANSTI Breathing Rates for SCUBALAB

The top graph was taken at 132 feet at 15 breaths per minute, and recorded a work-of-breathing score of .73 joules per liter — excellent performance, showing it was able to deliver air at that rate and depth with little effort. The next graph shows the same reg at 181 feet and a breathing rate of 30 breaths per minute. The denser air, higher water pressure and rapid breathing are taxing the reg, pushing its work- of-breathing score to 1.76 joules per liter — good, but a difference a diver would feel.

Where tec and rec meet, there’s a growing inventory of advanced gear like the Petrel 2 that’s user friendly and able to enrich the experience of recreational divers.

In closed-circuit or open-circuit trimix mode, it’s all about the tec side. But switch into Open Rec mode, and you’ve got a three-gas nitrox rec computer that’s easy to read and set, with a three-axis, tilt-compensated digital compass.

Targeted to tec divers, this multimode dive computer offers Gauge and Recreational Nitrox mode in addition to the OC Tec and OC/CC modes. It offers up to five open-circuit and five closed-circuit gases.